Biopsy device with inner cutting member

ABSTRACT

The invention is directed to devices and methods for separating and collecting a tissue specimen from a patient&#39;s target site. The device includes a probe member with a penetrating distal tip and a tissue receiving aperture, and a tissue cutting member which is rotatable disposed within the probe member to cut a tissue specimen drawn into the interior of the device through the aperture. The longitudinal edges of the aperture are preferably sharpened to engage the cutting edges of the tissue cutting member. Vacuum may be provided in the inner lumen of the cutting member to transport tissue therethrough. Rotation, rotational oscillation and/or longitudinal reciprocation of the tissue cutting member is effective to separate a tissue specimen from surrounding tissue. An accessing cannula having an tissue receiving aperture may be concentrically disposed within the probe member and about the tissue cutting member. The tissue cutting edge of the tissue cutting member preferably is longitudinally oriented and may have a cutting angle less than 90° with respect to the longitudinal axis of the tissue cutting member.

RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/793,465,filed Jun. 3, 2010, now U.S. Pat. No. 8,460,204, which is a continuationof application Ser. No. 10/642,406, filed Aug. 15, 2003, now U.S. Pat.No. 7,819,819, which is a continuation-in-part of application Ser. No.10/374,915, filed Feb. 24, 2003, now U.S. Pat. No. 7,189,206, all ofwhich are incorporated herein in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to tissue removing devices suchas biopsy devices and the methods of using such devices. Morespecifically, it is directed to a device and method for accessing andremoving pathologically suspect tissue from within a patient's body.

BACKGROUND OF THE INVENTION

In diagnosing and treating certain medical conditions, such aspotentially cancerous tumors, it is usually desirable to perform abiopsy, in which a specimen of the suspicious tissue is removed forpathological examination and analysis. In many instances, the suspicioustissue is located in a subcutaneous site, such as inside a human breast.To minimize surgical intrusion into the patient's body, it is desirableto be able to insert a small instrument into the patient's body toaccess the targeted site and to extract the biopsy specimen therefrom.

Electrosurgical techniques have been used in a variety of biopsyprocedures. In electrosurgery, high frequency electrical energy istypically applied to patient tissue through an active electrode, theelectrical circuit being completed by a return electrode in contact withthe patent's tissue. Electrical energy flowing through the tissue fromthe active electrode is effective to ablate tissue near the activeelectrode, forming an opening in the tissue and so allowing insertion ofthe instrument into a patient's body. A return electrode may be placedon the exterior of the patient's body or may be incorporated into thedevice itself. The return electrode is typically attached to the patientat a point remote from where the primary or active electrode contactsthe tissue. However, in the case of a bipolar electrode for example, thereturn electrode may be disposed near to the active electrode. Anelectrosurgical biopsy instrument is disclosed and claimed in U.S.patent application Ser. No. 09/159,467 for “Electrosurgical BiopsyDevice and Method,” now U.S. Pat. No. 6,261,241, assigned to theassignee of the present application, and which is hereby incorporated byreference in its entirety.

While these electrosurgical biopsy devices have been found to beeffective in many instances, they are not suitable for use inconjunction with magnetic resonance imaging.

SUMMARY OF THE INVENTION

This invention is directed to biopsy devices and methods for accessingand collecting tissue from a patient utilizing such devices. Thesedevices provide access to a targeted tissue site and provide for theseparation and capture of a tissue specimen from supporting tissue atthe targeted site.

A tissue collection device having features of the invention includes anelongated probe with an outer member having a tissue penetrating distaltip, a tubular portion proximal to the distal tip, an inner lumenextending within the tubular portion and an opened section or aperturein the tubular portion which provides access to tissue at the targetedsite. The probe includes an elongated tissue-cutting member which ispreferably at least in part cylindrically shaped and which is slidablydisposed within the inner lumen of the outer tubular member. The tissuecutting member is provided with at least one tissue cutting surfacewhich is configured to sever tissue extending into the probe through theopen section or aperture of the outer member. The cutting edge on thetissue cutting member may be configured to rotationally and/orlongitudinally move to cut a tissue specimen. The cutting movement mayinclude oscillating rotational motion and/or reciprocating longitudinalmotion to sever specimen tissue from supporting tissue at the targetedsite. The cutting surfaces or edges are radially spaced from alongitudinal axis of the tissue collection device and are generallylongitudinally oriented over a length thereof, preferably at an angle inthe cutting direction (hereinafter the cutting angle) of less than 90°from the longitudinal axis or from a longitudinally oriented edge of thetissue receiving aperture of the outer tubular member. The cutting edgetakes the general curvature of the cylindrical body forming the cuttingmember.

In one embodiment of the invention, the cutting member has an innerlumen preferably extending to the proximal end thereof for tissuespecimen removal. Mechanical withdrawal of the tissue specimen may beemployed or the proximal end of the cutting member may be configured tobe in fluid communication with a vacuum source to aspirate the severedtissue specimen through the inner lumen of the cutting member to atissue collection station. A higher fluid pressure may be maintained inthe inner lumen of the cutting member distal to the tissue specimen toaid in transporting the specimen proximally through the inner lumen. Inthis manner, the mechanical withdrawal and/or the vacuum on the proximalend of the specimen and a higher pressure on the distal end of thespecimen cn move the specimen through the inner lumen of the cuttingmember to a tissue collection station.

In at least one embodiment, the probe of the tissue collection device issecured, preferably releasably secured, to a drive housing provided withat least one drive unit. The tissue cutting member is operativelyconnected to the at least one drive unit to provide the desired cuttingmotion. The proximal end of the outer cannula is releasably secured tothe drive housing so that the orientation of the outer cannula withrespect to the housing can be selected before the probe is inserted intothe patient.

The probe may be provided with a tubular tissue accessing cannula whichis concentrically disposed between the outer tubular member and thetissue cutting member and a distal portion of the accessing cannula isprovided with a tissue accessing aperture. The tissue accessing cannulais connected by its proximal end to a drive unit within the housing torotate the cannula to adjust the orientation of the tissue receivingaperture about the longitudinal axis of the accessing cannula. Aproximal extremity of the cutting member is connected to a second driveunit or units to effect the rotation and any longitudinal motion desiredfor cutting the tissue specimen

A method of cutting and collecting a tissue specimen with a tissuecollection device embodying features of the invention includes advancingsuch a device at least partially into tissue at a desired site withinthe patient's body with the tissue penetrating distal tip of the outercannula disposed distal to the tissue to be separated from the targetsite. The inner lumen of the accessing cannula or the interior of theouter tubular member is exposed to tissue through the accessing apertureand the tissue is drawn into the accessing cannula by applying a vacuumto the inner lumen. A cutting member within the probe of the biopsydevice may then be moved to cut a tissue specimen from supporting tissueat the target site by rotational and/or longitudinal motions whichpreferably includes oscillating rotational movement and/or reciprocatinglongitudinal movement. Vacuum may be applied to the inner lumen of thecutting member, to pull or aspirate the tissue sample proximally. Inaddition, or alternatively, a higher fluid pressure may be maintained ina distal portion of the inner lumen distal to the specimen to push thetissue specimen proximally or the specimen may be mechanicallywithdrawn. Fluid pressure may include pressure from a liquid deliveredinto the interior of the device, such as a physiological salinesolution, and may include a gas, such as pressurized carbon dioxide,nitrogen or air, delivered into the interior of the device. Access toambient air can also maintain a sufficiently high pressure differentialto move the specimen through the inner lumen of the cutting member.Anesthetic may be injected to the target site through the outer cannulaor the inner lumen of the cutting member. Upon removal from the patient,the tissue specimen may then be subjected to pathological examination.After acquisition of a tissue specimen or specimens, the biopsy devicemay be withdrawn from the patient.

The outer tubular member of the probe provides the support for the probeto enable precise location of the accessing port to the desired locationat the target site with its longitudinal orientation being preset beforethe device is introduced into the patient. If an accessing cannula isprovided with the biopsy device, the accessing cannula is rotated tofurther position the tissue accessing aperture to the desired specimentissue and also to relocate the accessing aperture about or along thelongitudinal axis of the device for taking further specimens. Thecutting member quickly and cleanly severs the tissue specimen from thesupporting tissue to provide a better tissue specimen for pathologicalexamination.

These and other advantages of the invention will become more apparentfrom the following detailed description of the invention and theaccompanying exemplary drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view, partially in section, of an elongatedtissue biopsy system having features of the invention.

FIG. 2 is a perspective view of the distal portion of the outer memberor cannula of the biopsy device shown in the FIG. 1.

FIG. 3 is a transverse view, partially in section, of the proximal endof the distal tip of the outer member shown in FIG. 2 taken along thelines 3-3.

FIG. 4 is a perspective view of the distal portion of the tissueaccessing cannula of a biopsy device shown in FIG. 1.

FIG. 5 is a transverse cross-sectional view of the tissue accessingcannula shown FIG. 4 taken along the lines 5-5.

FIG. 6 is a perspective view of the distal portion of the tissue cuttingmember of the biopsy device shown in FIG. 1.

FIG. 7 is a transverse cross-sectional view of the tissue cutting membershown in FIG. 6 taken along the lines 7-7.

FIG. 8 is a perspective view of the proximal end of the biopsy deviceillustrating the releasable connection between the proximal end of theprobe and the housing.

FIGS. 9A and 9B are schematic transverse cross-sectional views of theprobe shown in FIG. 1 in open and closed configurations respectivelywith the aperture of the tissue accessing device opening to the left.

FIGS. 10A and 10B are schematic transverse cross-sectional views of theprobe shown in FIG. 1 in open and closed configurations respectivelywith the aperture of the tissue accessing device opening upwardly.

FIGS. 11A and 11B are schematic transverse cross-sectional views of theprobe shown in FIG. 1 in open and closed configurations respectivelywith the aperture of the tissue accessing device opening to the right.

FIGS. 12A and 12B are schematic transverse cross-sectional views of theprobe shown in FIG. 1 in open and closed configurations respectivelywith the aperture of the tissue accessing device opening downwardly.

FIG. 13 is a perspective view of the distal portion of an alternativedesign for the probe embodying features of the invention in a closedcondition.

FIG. 14 is a top plan view of the tissue cutting member of the probeshown in FIG. 13 with an inclined cutting edge.

FIG. 15 is a perspective view of the probe shown in FIG. 13 partiallyopen.

FIG. 16 is a perspective view of the probe shown in FIG. 13 with theleading distal cutting edge depicted.

FIG. 17 is a perspective view of the probe shown in FIG. 13 furtherrotated from that shown in FIG. 16.

FIG. 18 is a perspective view of the probe shown in FIG. 13 with theaperture of the outer member almost closed.

FIG. 19 is a perspective view of the distal portion of a tissue cuttingmember of a biopsy device embodying features of the invention.

FIG. 20 is a perspective view of the cutting member of the biopsy deviceshown in FIG. 19 slidably disposed within an outer cannula of the biopsydevice.

FIGS. 21A, 21B and 21C are schematic transverse cross-sectional viewstaken along the lines 21-21 shown in FIG. 20 depicting the reciprocatingmotion of the cutting member.

FIG. 22 is a plan view of the tissue receiving aperture in the distalportion of the device illustrated in FIG. 20 to further illustrate thereciprocating rotational and longitudinal motion of the cutting membershown in FIG. 20.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-7 illustrate a system 10 which includes a biopsy device 11embodying features of the invention. The biopsy device 11 generallyincludes an elongated shaft or probe 12 having an outer tubular memberor cannula 13 with a tissue penetrating tip 14 on the distal end thereofand an open tissue accessing region 15, a tissue accessing cannula 16and a tissue-cutting member 17 with a tissue cutting edge 18 which ispreferably at an angle θ with respect to the longitudinal axis 19. Theproximal end of the outer tubular member 13 is releasably secured to adrive housing 20 to provide a plurality of discrete orientations to theouter member 13. The housing 20 is provided with a drive unit (notshown) configured to provide motion to the tissue accessing cannula 16and the tissue cutting member 17. A tissue specimen collection station21 is connected in a fluid flow relationship with the tissue cuttingmember 17 through conduit 22 and is connected to a vacuum source (notshown) through conduit 23.

As shown in more detail in FIG. 2 the outer member 13 has an elongatedtubular body 24 with an inner lumen 25 which is configured to receiveand support the accessing cannula 16. The distal end of inner lumen 25opens to the tissue accessing space between the distal end of thetubular body 24 and the proximal end of tissue penetrating tip 14. Aconnecting strut or wall portion 26 extends between the tissuepenetrating distal tip 14 and the tubular body 24 of the outer member13. As shown in FIG. 3, the proximal end 27 of the penetrating tip 14 isprovided with a first circular groove 28 which is configured to receivethe distal end of the accessing cannula 16 as shown in FIGS. 1 and 3 anda second circular groove 29 which is configured to receive the distalend of tissue cutting member 17. The penetrating distal tip 14 may havea variety of tip shapes in addition to the conical shape shown and mayhave an arcuate RF electrode such as disclosed in U.S. Pat. No.6,261,241, and U.S. Pat. No. 6,471,700, both assigned to the presentassignee and both are incorporated herein in their entirety. The widthand length of the strut 26 is sufficient to provide required support tothe distal tip 14 and may vary depending upon the strength of thematerial from which it is made. A stiffening rib may be provided to theunderside of the strut for structural stiffness. Multiple struts may beused, provided that a large enough opening is available for tissueaccess to the aperture 27 of the accessing cannula 16.

As best shown in FIGS. 4 and 5, the accessing cannula 16 has a tubularbody 30 which defines at least in part the tissue receiving aperture 27.The tubular body 30 has an inner lumen 31 which is configured toslidably receive the tissue cutting member 17. The aperture 27 isconfigured to receive tissue for the specimen of suitable size. Thearcuate length of the side edges 32 and 33 forming the aperture 27. Theaccessing cannula 16 is configured at its proximal end to be operativelyconnected to a drive unit (not shown) to rotate the tubular body 30about longitudinal axis 34 to provide a desired orientation to theaperture 27.

The tissue cutting member 17, as depicted in FIGS. 6 and 7, is formed oftubular member 35 which has an inner lumen 36 and which has an arcuatewall portion 37 forming side cutting edge 18. The tissue cutting edge 18may be a sharpened edge of the arcuate wall portion 37 or it may be ablade (not shown) secured to the edge. The cutting edge 18 should belonger than the length of the aperture to ensure complete severance ofthe tissue specimen from the supporting tissue at the target site uponrotation of the cutting edge 18. The tissue cutting member 17 is rotatedto effect tissue cutting by cutting edge 18, but the member may also beprovided with reciprocating longitudinal movement in addition to therotational movement thereof to provide a cleaner tissue cut. Both edgesof the arcuate wall portion 37 may be sharpened or provided with bladesfor tissue cutting purposes. The cutting edge 18 is spaced radially fromthe longitudinal axis of the probe and inclined at an acute cuttingangle θ with respect to the longitudinal axis 34.

FIGS. 1 and 8 illustrate the releasable connection between the outermember 13 and the housing 20 to allow for a plurality of discreteorientations of the tissue receiving space of the outer member. Asshown, the proximal end of the tubular portion 24 of outer member 13 isprovided with a plurality of longitudinally extending upstanding ribs 38spaced about the periphery of the tubular portion 24. A correspondingnumber of recessed passageways 39 are disposed about the opening 40 inthe distal face 41 of housing 20 designed to receive the ribs 38.Arcuate ridges 42 are provided between the ribs 38 to receive tooth 43of releasable locking mechanism 44 provided in the interior of housing20. The mechanism 44 for releasably locking the proximal end of theouter member 13 may take a variety of configurations. The particularmechanism 44 shown in FIG. 8 is preferably manually operated by thefingers of the operating physician. The operator 45 is pivotallyconnected within the housing 20 at an intermediate location so thatdownward pressure on button 46 in the top portion of the housing 20connected to elongated member 47 presses the proximal end of operator 45raising the distal end and the tooth 43 to release the tooth 43 from theridge 42 to allow for movement of the proximal end of tubular portion 24of outer member 13 with respect to the housing 20. The distal end of themechanism 44 is biased upwardly by spring 48 so that when the proximalend of the outer member 13 is inserted into opening 40 the tooth 43rides up ramping surface 49 on the proximal end of the ridge 42 andseats and is locked on the front face of ridge 42.

The drive housing 20 and attached probe 11 allows the entire unit to bedisposable. The drive units within the housing control the motion of theaccessing cannula 16 to orient the aperture 27 and the motion of thecutting member 17 which may be rotation or rotation and longitudinalreciprocation. Other means (not shown) may provide mechanical andelectrical power, vacuum, and control to the probe device. Examples ofreplaceable snap-in type drive units are disclosed in Burbank et al.,U.S. patent application Ser. No. 10/179,933, “Apparatus and methods forAccessing a Body Site” hereby incorporated by reference in its entirety.Drive units such as that described in WO 02/069808 (which corresponds toco-pending U.S. application Ser. No. 09/707,022, filed Nov. 6, 2000 andU.S. application Ser. No. 09/864,021, filed May 23, 2001), which areincorporated herein by reference, may be readily modified by thoseskilled in the art to accommodate the movement of the accessing cannula16 and the cutting member 17.

FIGS. 9A and 9B, 10A and 10B and 11A and 11B schematically illustratethe operation of the device 11 and the rotation of the probe 12 todiscrete orientations. This series of sketches depict the sequencing oftaking tissue specimens from below or the bottom side of a target site.In FIG. 9A the aperture 16 is open to the left with the arcuate wallportion 40 in a non cutting position. A vacuum is applied to the innerlumen 31 of the tissue cutting member 17 and tissue 50 (shown inphantom) from the target site is pulled into the interior of theaccessing cannula 15 through the aperture 16. In FIG. 9B the arcuateportion 37 of tissue cutting member 17 is rotated to sever the aspiratedtissue 50 from the supporting tissue at the target site with the cuttingsurface 18. The vacuum within the inner lumen 31 of the tissue cuttingmember 17 causes the tissue specimen to be drawn through the inner lumenand into the collection station 21 shown in FIG. 1. Positive pressure oreven ambient conditions distal to the tissue specimen can facilitatetissue passing through the inner lumen 31. The accessing cannula 15 isthen rotated so that the aperture 27 is facing upwardly as shown in FIG.10A and as shown in FIG. 10B the procedure for cutting the tissuespecimen is repeated. In FIGS. 11A and 11B the aperture 27 is open tothe right and the procedure is again repeated for additional specimens.Other intermediate positions for the aperture 27 are possible. When thetarget site is accessed from the upper portion thereof, the probe device11 is released from the housing 20 and then is inverted or turnedthrough 180° so that the strut 26 is on top as shown in FIGS. 12A and12B with the aperture 27 open downwardly. The housing 20, not shown inthese drawings, may remain in the same orientation. The same motion forthe accessing cannula 16 as described above may be used to obtain asimilar series of tissue specimens from the top of the target site. Ifthe target site is large enough, the probe may pass through the site andaccessing may occur from within the interior of the target site in thesame or similar manner as that discussed above for accessing the tissuefrom the top or bottom of the tissue site.

FIGS. 13-18 illustrate a probe 60 for a biopsy device embodying featuresof the invention. In probe 60 the outer member or cannula 61 has atissue receiving aperture 62 for receiving tissue from the target site.The outer member 61 has a sharp distal tip 63 shown in phantom which isconfigured to easily penetrate through tissue to the target site. Tissuecutting member 64 is rotatably disposed within outer member 61 and has aproximal end (not shown) operatively connected to one or more driveunits within housing (not shown) for imparting cutting motion theretosuch as previously described herein. The inner lumen 65 of tissuecutting member 64 is configured for fluid communication with a vacuumsource (not shown) to urge a tissue specimen through the inner lumen 65.As mentioned with the description of the embodiment shown in FIG. 1-7,positive pressure or even ambient conditions will aid in passing thesevered tissue through the inner lumen 65 of tissue cutting member 64.The tissue cutting member 64 has an aperture 67 as shown in FIG. 14defined in part by cutting edge 68 and non-cutting edge 69. The cuttingsurface is longitudinally oriented at an angle with respect to thelongitudinal axis of the tissue cutting member 64. The cutting surfaceor edge 68 has a distal leading cutting edge portion 70 and a proximaltrailing cutting edge portion 71. This tissue cutting member structureprovides better application of vacuum to tissue at the target site andas a result provides better control of the tissue cutting. The cuttingaction for this embodiment is shown in the sequence shown in FIGS. 13and 15-18. In FIG. 13, the aperture 62 of the outer member 61 is closedby the arcuate wall portion 73 of tissue cutting member 64. Thenon-cutting edge 69 of tissue cutting member 64 first appears at thedistal end of aperture 67 as shown in FIG. 15. Application of vacuumbegins to pull tissue from the target site into the interior of thetissue cutting member at the distal location. As the tissue cuttingmember 64 rotates (as shown in FIGS. 16-18) the non-cutting edge 69first appears to allow tissue to be pulled into the inner lumen 65 ofthe tissue cutting member and the cutting edge 68 of the tissue cuttingmember follows, cutting off tissue pulled into the interior of thecutting member from the supporting tissue at the target site startingfrom the leading cutting edge portion 70 to the trailing proximalcutting edge portion 71 along the length of the aperture 67.

FIG. 19 illustrates a tissue cutting member 80 which embodies featuresof the invention and which has an elongated cylindrically shaped body 81with a distal cutting section 82. The distal cutting section 82 has abeveled, needle-like distal tip 83 with a sharpened opposed edges 84 and85 which facilitate cutting of the tissue specimen when the cuttingmember 80 is moved within the outer tubular member or cannula 86 (asshown in FIG. 20). A longitudinal slot 87, which preferably tapers tosmaller transverse dimension in the proximal direction, is provided inthe distal cutting section 82 at the proximal ends of the sharpenededges 84 and 85 and a transverse slot 88 is provided at the proximal endof slot 87 to facilitate slight flaring of the distal cutting section 82as shown by line 89. The outward bias of the sharpened edges 84 and 85ensures that these edges engage the longitudinal edges 90 and 91 of theaccessing aperture 92 of the outer cannula 86 as shown in FIG. 20 toprovide a scissor-like cutting motion for severing a tissue specimenfrom supporting tissue at the target biopsy site.

FIGS. 21A-21C and FIG. 22 illustrate the oscillating and longitudinalmotions of the cutting member 80 within the outer cannula 86 as thecutting member is advanced distally. FIGS. 21A-21C are highly schematictransverse cross-sectional views illustrating the rotationaloscillation. In FIG. 21A the beveled tip 83 is centrally positionedwithin the accessing aperture 92. In FIG. 22B the cutting member 80 hasrotated toward the cutting edge 90 of aperture 92 with cutting edge 84of the cutting member 80 engaging the edge 90 in a scissor-like fashion.In FIG. 21C the cutting member has rotated to the cutting edge 91 ofaperture 92 with the cutting edge 85 of the cutting member 80 engagingthe cutting edge 91 in a scissor-like fashion. As shown more clearly inFIG. 22, the cutting member 80 moves longitudinally as it isrotationally oscillated so that the flared cutting edges 84 and 85engage the edges 90 and 91 of the length of the accessing aperture 92 toprovide scissor-like, tissue cutting action. The cutting actionpreferably continues until the beveled tip 83 has completely traversedthe aperture 92 and the tissue specimen has been completely severed fromsupporting tissue at the biopsy site. A vacuum may be applied to theinner lumen 93 of the cutting member 80 to aspirate the severed tissuespecimen to the proximal end of the biopsy device where the specimen maybe removed. Positive pressure or access to ambient conditions may beprovided in the distal tip of the outer cannula 86 to aid in thespecimen transfer through the inner lumen 93 of the cutting member 80.The cutting edges 84 and 85 have cutting angles θ with respect tocutting edges 90 and 91 (which are generally parallel to thelongitudinal axis 94) of about 20° to about 80°, preferably about 30° toabout 75°, over most of the length of the cutting edges 84 and 85.However, at the proximal and distal ends of the beveled tip, the cuttingangle may approach 90°.

The cutting member 80 is positioned in its most forward position closingoff aperture 82 when the biopsy device 93 is advanced to the desiredbiopsy site. The cutting member is then pulled proximally to expose adesired length of the aperture 82 which controls the length of thespecimen to be severed from the supporting tissue. The cutting member 80is then advanced distally with a side-to-side oscillation to severtissue drawn or otherwise extending into the interior of the outercannula 86. The cutting member 80 may also be provided with longitudinalreciprocating motion to aid in severing the tissue specimen from thesupporting tissue at the biopsy site.

The elongated shaft or probe of the biopsy device has a length of about3 to about 15 cm, preferably, about 5 to about 13 cm, and morespecifically, about 8 to about 9 cm for breast biopsy use. To assist inproperly locating the probe of the device during advancement thereofinto a patient's body, (as described below), the distal extremity of thevarious members may be provided with markers at desirable locations thatprovide enhanced visualization by eye, by ultrasound, by X-ray, MRI orother imaging or visualization means. Manual palpation may also beemployed. An echogenic polymer coating that increases contrastresolution in ultrasound imaging devices (such as ECHOCOAT™ by STSBiopolymers, of Henrietta, N.Y.) is suitable for ultrasonicvisualization. Radiopaque markers may be made with, for example,stainless steel, platinum, gold, iridium, tantalum, tungsten, silver,rhodium, nickel, bismuth, other radiopaque metals, alloys and oxides ofthese metals. In addition, the surfaces of the device in contact withtissue or other components of the device may be provided with a suitablelubricious coating such as a hydrophilic material or a fluoropolymer.

The outer member or cannula, the accessing cannula and the tissuecutting member are preferably formed of stainless steel. However, otherhigh strength materials such as MP35N, other cobalt-chromium alloys,NiTi alloys, ceramics, glasses, and high strength polymeric materials orcombinations thereof may be suitable.

A patient's skin usually must be breached in order to gain access to abody site where a tissue specimen is to be obtained. A scalpel or othersurgical instrument may be used to make an initial incision in the skin.After the specimens have been taken, the biopsy device may be removedfrom the patient. The entire device may be removed; however, in someembodiments, the outer member may remain within a patient's body to aid,for example, in the acquisition of further tissue specimens and in theplacement of markers at the site from which a tissue sample was taken.In addition, it will be readily appreciated that other types ofinstruments may be inserted into the tissue site through the fixed outercannula or accessing cannula in addition to or in place of theinstruments described above.

While particular forms of the invention have been illustrated anddescribed herein, it will be apparent that various modifications andimprovements can be made to the invention. For example, while thevarious embodiments of the invention have been described herein in termsof a biopsy device, it should be apparent that the devices and methodsof utilizing the device may be employed to remove tissue for purposesother than for biopsy, i.e. for treatment or other diagnoses. Moreover,individual features of embodiments of the invention may be shown in somedrawings and not in others, but those skilled in the art will recognizethat individual features of one embodiment of the invention can becombined with any or all the features of another embodiment.Accordingly, it is not intended that the invention be limited to thespecific embodiments illustrated. It is therefore intended that thisinvention to be defined by the scope of the appended claims as broadlyas the prior art will permit.

Terms such a “element”, “member”, “device”, “sections”, “portion”,“section”, “steps” and words of similar import when used herein shallnot be construed as invoking the provisions of 35 U.S.C. § 112(6) unlessthe following claims expressly use the terms “means” or “step” followedby a particular function without specific structure or action. Allpatents and patent applications referred to above are herebyincorporated by reference in their entirety.

What is claimed is:
 1. A biopsy device comprising: a. an outer cannulawith a distal end, a tissue receiving aperture proximal to the distalend and an inner lumen extending within the outer cannula to the tissuereceiving aperture; and b. an elongated tissue cutting member disposedwithin the inner lumen of the outer cannula, the elongated tissuecutting member comprising, i. a distal tubular portion having a beveleddistal tip with opposed outer distal tissue cutting edges comprised of afirst distal cutting edge portion and a second distal cutting edgeportion, and configured such that the first distal cutting edge portiontransitions to the second distal cutting edge portion at a distal extentof the beveled distal tip, the opposed outer distal tissue cutting edgesconfigured to cut a tissue specimen from tissue extending into thetissue receiving aperture in the outer cannula, the distal tubularportion having a longitudinally extending tapered slot configured toform a separation between the first cutting edge portion and the secondcutting edge portion at a perimeter of the distal tubular portion, thetapered slot widening in a distal direction toward the beveled distaltip to facilitate an outward flaring of the distal tubular portion, andii. a proximal tubular portion having an inner lumen configured toreceive the tissue specimen cut by the opposed outer tissue cuttingedges.
 2. The biopsy device of claim 1, wherein the proximal tubularportion of the elongated tissue cutting member is connected to a drivemember to simultaneously rotationally oscillate and distally advance theelongated tissue cutting member within the inner lumen of the outercannula.
 3. The biopsy device of claim 2, wherein the distal advancementof the elongated tissue cutting member is a longitudinal reciprocatingmotion.